But the Government and opposition parties have all defended the expense, saying the mission was a long-term investment that would attract new business for Ireland.

The LE Niamh's 18,000 nautical mile mission in May of this year cost €635,468 in fuel alone. The remainder of the bill covered port fees, entertainment, deck maintenance and provisions.

During the 10-week trip, the IDA, Enterprise Ireland and An Bord Bia used the vessel as a platform for attracting new business and investment in Mexico, Argentina, Colombia and Chile. More than 12,000 people visited the ship. A trip to Asia in 2002 cost €250,000 -- a third of the 2010 bill.

Defence Minister Tony Killeen said that in the current climate promoting Ireland abroad had taken on greater importance.

Both Labour's Brian O'Shea and Fine Gael's David Stanton last night backed the trade mission.